Heavy particle therapy (such as proton therapy or heavy ion therapy) and/or hadron therapy (e.g., treatments that deliver pions) may be used to treat tumors within a human patient. In general, heavy particle therapy involves aiming energetic ionizing particles accelerated by a particle accelerator toward a target tumor. Because of their relatively large mass, the heavy particles have a relatively localized deposition of energy within the tissue. Thus, as compared to other radiation treatments, heavy particle therapy may be less likely to cause damage to surrounding tissue.